Internal-combustion engine



J. FROELICH.

INTERNAL CVOMBUSTION ENGINE. APPLICATION FILED Nov.25.191z.

1,332,211, Patented m1124920.

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I. FHOELICH.

INTERNAL COMBUSTION ENGINE APPLICATION FILED NOV. 25 i917.

l ,332,2 l I I Patented Mar. 2, 1920.

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-L FROELICH.

vINTERNAL COMBUSTION ENGINE AfPLlcATloN msn Nov. 25. lsu.

1,332,21 1. l Patented Mar. 2, 1920.

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291,7; @v1/iov" John FToeZ-ck Z5 y Wawy JOHN lrnonmcn, or sT. PAUL, nINNnsoTA.

INTERNAL-CQMBUSTION ENGINE.

.Specification o Letters Patent.

.Patented Mar. 2, 1920.

Application led 0ctober25, 1917, Serial No. 198,403.

To all whom t may concern.'

Be it known that I, JOHN FRoELIc-H, a citizen of `the United States, 4residingat St. Paul, in the county .of vRamsey and 'State of Minnesota, lhave invented ynew and useful Improvements in Internal-Combustion Engines, of Which the following is a specification.

My invention relates to improvements in internal combustion engines, .and is a simplified form-of `the 'two-.cycle internal combustion engine in which :the .cylinders .are arranged in pairs and coperate witheach other inthe introduction of fuehras heretofore described in my `application :for patent filed December 3, 1915, and bearing Serial No. 64,890.

lIihe general objectspof the invention are to provide a simple and efficient engineof the piston-valve type kr'having means `for thoroughly scavenging 'the cylinders after each explosion vand for introducing .charges of fuel of uniform quantity and composition into the cylinders, and ,also to produce an operating cycle lin Whichthe scavenging and introduction of charges of --uel .shall be so related as vto result in increased efiic-iency.

A Ifurther object is to simplify the construction embodied in my application Serial Number 64,890, and eliminatethe possibility of escape through the exhaust ports or' unburned vgases prior to the covering of such ports by the piston.

Other novel featuresofconstruction will be rhereinafter described and pointed out `in the claims. y

'In the accompanying drawings, Figure-1 is a longitudinal sectional view vof my engine; Fig. 2 lis a lcent-ral transversev sectional view taken through one of the engine cylinders and illustrates the `pistonvalve arrangement and the various ports and passageways; Fig. 3"is a vertical section taken on the line 3-3 of Fig. 2; Fig. 4 iS a section on the line 4-4 of Fig. 2; Fig. 5 is a section ontheline 5-5of Fig. 2;:and Figs. 6, 7, and 8 are diagrammatic views, each showing the cylinders )of the `engine with the moving parts in different rela-tive positions.

Referring to the drawings, I have used the reference letters .A yand -B to indicate the differential `cylinders. These y Cylinders are identical 'and ,are .amounted .side lby side upon a lcranlntase C having therein a removable dividing Wall C formed of separable sections adapted to divide said crankcase into compartments, one for each cylinder. A crankshaft 1 revoluble in the crankcase vis formed with a crank 2 in each compartment, said cranks being' arranged at 180 with respect toeach other. Differential pistons A and B Within the cylinders A and B `respectively are connected by pitmen 3 :to said cranks 2, and move in opposite directions.

The differential cylinders A and B comn inlet and outlet `port 9", 9b, which permits the passage of gas into and out of said chambers. The compartments or air compression chambers 10a, 10" in the crankcase vCareyprovided with channels 113,11", communicating respectively With the air inlet ports da, 6b -in theexplosion chambers. A puppet-.valve 12 for each compartment 10, 10b .is placed at one side ofthe crankcase and admits air to I`its lsaid compartment. 'Ehe `differential `pistons A, B comprises respectively Working `pistons a and .o and pump pistons a and b', the former litting the explosionchambers 4a, 4". and the latter the pump chambers 5a, 5b. `The Working pistons a and Z compress gas Within the explosion chambers 4a, 4b and receive .impulses upon the ignition of the gas, While the-pump pistons a and l2 serve a double purpose, namely: Yto draw gas into the lpump chambers, .5b and expel the same therefrom kand also to draw air into the air compression 4chambers 10, 10b and compress -said `-air therein. Deflectors 37 are placed .upon the topof said pistons A', B and force air-and gas (both introduced under pressure against the top of the explosion chambers 4, `4b.

Ahousing D, containing .two oppositely working piston-valves E and F and a shaft 13, having oppositely arranged cranks 14, is arranged on the admission side of the cylinders A and B. Pitmen 15 connect said piston-valves E and F to the cranks 11 on said shaft and said shaft is journaled in the housing D and revolved at the same rate of speed as the main crankshaft 1 by means of a train of gears 16 driven by said main crankshaft. A casing 17 incloses said gears, and together with the housing D, completely incloses the valve mechanism of my engine.

Within the upper end of the housing D are situated two valve cylinders 18JL and 181, each having a machined valve-liner 20 rigidly secured therein, within which the piston-valves E and F respectively travel. Said valve-liners 20 prevent leakage around ,said valves and facilitate the accurate positioning of the valve ports hereinafter described.

A horizontal partition 21 in the upper end of the housing D forms a storage or transfer chamber G, within which the upper ends of the valve cylinders 18a, 181 project. Apertures 22 are formed in the projecting ends of said valve cylinders and two additional ports 23a, 231 are formed in said valve cylinders 18, 181 respectively at the bottom of said transfer chamber G; said ports 23a, 231 and apertures 22 respectively permitting the admission and exit of gas to and from said transfer chamber. Below said ports 23, 231 in the valve-cylinders 1S, 181 are located channels 25a, 251 which communicate with the exterior of the housing D and said valve cylinders 18a, 181 respectively, and provide a passageway for gas from a carbureter (not shown) to the piston-valves E and F. Port-s 27a, 29a, and 271, 291 are formed in the opposite sides of said valve cylinders 18a, 181 respectively, and channels 31, 311 respectively provide means of communication between said ports 27a, 271 and the gas admission ports 8, 81; while channels 33, 331 perform a similar function between the ports 29, 291 and pump chamber ports 9, 91. Each piston-valvevE and F has two converging passageways 35, 36a and 351, 361 respectively extending diametrically therethrough; the direction of convergence being toward the engine cylinders, and said passageways 35, 351 are so positioned that during substantially one-third of a revolution of the shaft 13 (and likewise of the main crank shaft 1), said passageways 35, 351 register with the ports 23, 29 and 231, 291 respectively; while during substantially the opposite one-third revolution of said shaft the passageways 36, 361 register with the channels 25", 251 and ports 29, 291. y

The operation of my engine will now be described, taking as a convenient starting point in the operating cycle the explosion of a charge in one of the cylinders. Beginning with an explosion in the cylinder A (Fig. 6), the differential piston A moves downward upon its forward stroke, the piston a compressing air in the compression chamber 10a, the puppet-valve 12 now being closed, and the air inlet port 6 in the cylinder being covered by the piston a. The suction thus caused in the pump chamber 5a by the downwardly moving piston a draws gas fromA a carbureter (not shown) communicating with the channels 25a, 251 through said channel 25a, thence through the passageway 36a in the piston-valve E, and through the port 29a in the valve cylinder 18a, and thereafter through the passageway 33a and into the pump chamber 5a. The differential piston B is carried upward during such downward stroke of the differential piston A and its piston b draws a. supply of air through the puppet-valve 12 into the compression chamber 101 and compresses the gas for a short interval in the pump chamber 51, then forces said gas through the port 91 and channel 331 into the transfer ,chamber G through the passageway 351 in the piston-valve F, which now registers with the ports 291 aud 231 in the valve cylinder 181.

Just before the piston A reaches the end of its forward-stroke (Fig. 7), the gas admission port 8a, vair inlet port 6, and eX- haust port 71 of the explosion chamber L1, are uncovered by said piston. The uncovering of the exhaust port 7a releases the burnt gases and the opening of the air inlet port 6a permits the infiow of scavenging air from the air compression chamber 10L through the channel 11a. This inflowing current of air strikes the baffle-plate or deflector 37 on the top of the piston a and is first deflected upward to reach and drive out all of the burnt gases through the exhaust port 7*.

No gas is admitted to the explosion cham- 119 ber at this point, the piston-valve E blocking the channel 311cmmunicating with the gas admission port 8a. The companion piston B at this time is completing the com-` v pression of the gas in the explosion chamber 4:1, also completing the expulsion of the gas from the pump chamber 51, and further completing the intake of air to the compression chamber 101.

At the beginning of the return stroke of 120 the piston A in said cylinder A (Fig. 8), and after the air inlet port 6a is covered by the piston a (but before the exhaust port 7- is completely covered), the piston-valve E uncovers the port 27a in the valve cylinder 125` 18a and a charge 4of gas from the transfer chamber G first passes through the apertures 22 in the top of said valve cylinder 18a and then rushes through the gas admission port 8a into ythe explosion chamber 4a. The 130 influx of said gas displaces the scavenging air, as said scavenging air had displaced the burnt gas, thus resulting in supplying the explosion chamber with a complete charge of fresh gas upon the initial return movement of the piston A. Continued upward movement of said piston A operates to compress the gas within the explosion chamber ll, force the gas from the pump chamber 5 through the passageway 35a of the pistonvalve E, and into the transfer chamber G via the port 23, and also draw air through the puppet-valve l2 into the compression chamber 10a. This completes one turn of the crank-shaft and said operation is repeated upon each revolution thereof.

Having described my invention, what I claim as new and desire to protect by Letters Patent is:

l. In an internal combustion engine, a pair of differential cylinders, each comprising a pump chamber and an explosion chamber, said pump chambers each having a common inlet and outlet port and said explosion chambers each having a gas admission port, an air admission port and an eXhaust port, a crankcase divided into air compression compartments, one for each cylinder, channels connecting said air compression compartments of each cylinder with the air admission port in the same cylinder, a differential piston for each of said cylinders, comprising a power piston arranged to uncover said gas admission port, air admission port and exhaust port at the end of its power stroke, and a pump piston adapted to draw gas into the pump chamber and expel the same therefrom and `also draw air into the crankcase and compress said air therein, a transfer chamber, conduits connecting thc pump chamber of each cylinder with said transfer` chamber, and conduits connecting said transfer chamber with the gas admission ports of the explosion chambers, and a piston-valve for each cylinder designed to control the passage of gas to and from the pump chamber of its cylinder and also to admit gas into the explosion chamber immediately after the air admission port is covered by the power piston.

2. In an internal combustion engine, a pair of differential cylinders, each cylinderl having a pump chamber provided with an inlet and outlet port and an explosion cham cylinder, pistons in said cylinders working in opposite directions, a transfer chamber, a valve cylinder for each differential cylinder, separate passageways leading from a source of fuel supply to said valve cylinders, from said valve cylinders to the pump chamber and also to the explosion chamber of their respective diierential cylinders and from said valve cylinders to the transfer chamber, piston-valves for said valve cylinders, said piston-valves each having a plurality of ports and channels therein adapted to register with the passageways communicating with its valve cylinder to admit gas into the pump chamber of one cylinder, then direct said gas therefrom into the transfer chamber and finally to admit gas from said transfer chamber into the explosion chamber.

3. In an internal combustion engine, a pair of dierential cylinders, each cylinder having a pump chamber provided with an inlet and outlet port and an explosion chamber provided with an exhaust port, a crankcase divided into air compression chambers, one for each cylinder, said chambers communicating respectively with the explosion chambers of said cylinders, pistons in said cylinders working in opposite directions, a transfer chamber, a valve cylinder for each differential cylinder having a passageway communicating with a source of fuel supply, conduits leading from said valve cylinder to the pump chamber, and also to the explosion chamber of its said differential cylinder, and from said valve cylinder to the transfer chamber, piston-valves for said valve cylinders, each of said piston-valves having a plurality of ports and channels therein adapted to register with the passageways communicating` with its valve cylinder, whereby gas is admitted into the pump chamber of one cylinder, then directed by its piston-valve to the transfer chamber and admitted by the other piston-valve to the xplosion chamber of the companion cylin- Whereof, I have hereunto subscribed my name to this specification.

JOHN FROELICH. 

